1. Field of the Invention
The present invention relates to an intraluminal device for use in the treatment of aneurysmal or stenotic disease. Particularly, the present invention relates to endovascular emplacement of structures designed to enhance a patient's vasculature, particularly those areas of a patient's vasculature that do not have sizeable branches extending therefrom.
2. Discussion of the Related Art
An aneurysm is a ballooning of the wall of an artery resulting from weakening due to disease or other condition. Left untreated, the aneurysm may rupture, resulting in severe loss of blood and potentially death. An aneurysm in the abdominal aorta is the most common form of arterial aneurysm. The abdominal aorta, which extends downward from the heart in front of and parallel to the spine, through the thorax and abdomen, and generally branches off in a plurality of side vessels, connects the ascending aorta at the heart and to the circulatory system of the trunk and lower body. Branched vessels of the aorta supply the two kidneys via oppositely-directed renal arteries. Below the renal arteries in typical human anatomy, the abdominal aorta continues to about the level of the fourth lumbar vertebrae and divides at a Y-junction into the left and right iliac arteries, which supply blood to the lower extremities.
A common location for an aortic aneurysm is in the section of aorta between the renal and iliac arteries. Without rapid surgical intervention, a rupture of the abdominal aorta is commonly fatal because of the high volume of blood flow within the aorta. Conventional surgical intervention involves penetrating the abdominal wall to the location of the aneurysm to reinforce or replace the diseased section of the aorta. Typically, a prosthetic tube graft replaces the area of, or proximal and distal zones abutting, a potential rupture portion of the aorta. Unfortunately, conventional surgical intervention has resulted in substantial morbidity rates, and at the very least a protracted recovery period. Likewise, cost and other constraints militate for a longstanding need for endovascular intervention.
In recent years, methods and devices have been developed to treat an aortic aneurysm without opening up the abdominal wall. These new techniques typically involve a catheter-carried tubular graft delivered upward from the femoral artery through the iliac artery and into the region of the aneurysm. The graft normally includes a tubular graft body supported by an expandable stent, either self-expanding or balloon-expanding. The balloon-expanding type of stent naturally requires an expansion balloon, while the self-expanding type is simply deployed from the end of a tubular sheath. Emplacement issues impact upon both known techniques.
Endovascular grafts and stented grafts are generally known to be useful in several distinct configurations. For example, it is known to use intraluminal grafts and stents of various designs for the treatment of aneurysms such as aortic aneurysms, and occlusive diseases affecting the vasculature or other vessels comprising, inter alia, the hepto-biliary and genito-urinary tracts (which are all hereinafter “vessels”). It is known to form such an intraluminal device of a sleeve in which is disposed a plurality of wire stents (see Balko A. et al (1986) Transfemoral Placement of Intraluminal Polyurethane Prosthesis for Abdominal Aortic Aneurysms, 40 Journal of Surgical Research 305-309; Mirich D. Et al. (1989) Percutaneously Placed Endovascular Grafts for Aortic Aneurysms: Feasibility Study 170(3) Radiology 1033-1037).
In the past, such devices have commonly be used in the treatment of, or to exclude aneurysms, see, e.g., U.S. Pat. Nos.: 5,782,904; 5,986,068; 6,013,092; 6,024,729; 6,045,557; 6,071,307; 6,099,558; 6,106,540; 6,110,191; 6,143,014; 6,231,563; and 6,278,079, each of which is licensed or assigned to and may be available from Edwards Lifesciences LLC (Orange County, Calif.), the instant assignee, and each of which is expressly incorporated herein by reference.
Whatever the purpose for which an intraluminal device is being used, it has the capacity to be inserted percutaneously through a distal (or proximal) and connecting vessel to that in which the device is to be used. For example, it may be inserted through the femoral artery in a catheter, where the device is intended to be used in the treatment of a lesion within the aorta. Upon release of the device from the catheter it may expand or be expanded to a desirable size, and may extend above and below the lesion thereby bridging the lesion. This method of inserting the device into the body of a patient is applicable where the invention is used in the treatment of aneurysmal disease or stenotic disease.
There are several potential problems associated with most known intraluminal devices. For instance, conventional grafts are not designed to follow the natural curvature of some vessels and may, therefore, kink if required to bridge a section of vessel that has a natural curvature. Alternatively, some graft candidates have atypical vasculature. For example, some candidates have an aorta that does not funnel blood into two iliacs. This may be caused either by a complete occlusion in one iliac, or by a variation in an individual patient's vasculature. In the past, a bifurcated graft having one leg sewn shut or otherwise removed has been used to treat aneurysms or stenotic disease in these and other non-branching vessels. However, such alteration of the bifurcated graft generally does not provide as even a flow path as is desired. Additionally, this requires an additional step on the part of the administering physician. Furthermore, it may be difficult to use such a bifurcated graft as a conversion graft, or to supplement a failed or failing graft.
Despite much work in this highly competitive field, there is still a need for a graft that is specifically designed to be used with generally straight vasculature or vessels.